US Patent 12065636 High hydrogen utilization and gas recycle

Provided herein are systems and methods for recycling and supplementing off-gas from a gas fed reaction process. The systems and methods are particularly useful for bioprocesses that convert hydrogen gas into one or more biosynthetic products. By maintaining separate hydrogen and oxygen feed gas streams, and forming a recycle gas that introduces a target component of the supply gas to the bioreactor within a target concentration range, the yields, productivities, and safety profiles of the bioprocess can be enhanced.